The present invention generally to improvements in fittings for conduits such as pipes, tubes, ducts and the like and it relates particularly to an improved conduit fitting for connecting sections of conduit securing a conduit to a wall opening and for other applications.
In the transmission of electrical power or signals, it is a conventional practice to house the electrical transmission wire or cable in plastic or thin metal conduits. Since the electrical cable is generally longer than the lengths of the housing conduit sections and the cable terminates at a junction box, it is necessary to firmly connect the proximate ends of successive conduit sections and to firmly connect the terminal end of the joined conduits to a wall of a junction box through an opening of which the cable passes. Moreover, the conduit connections as well as the conduit junction box connection should be of a hermetically sealed nature. A conduit coupling which has heretofore been used consists of a collar oppositely internally threaded at opposite ends. While such coupling is simple and inexpensive, its use is highly inconvenient and awkward, requiring that the ends of the conduit sections be externally threaded to match the coupling threads, a procedure which possesses numerous drawbacks, since such operations are time consuming and require special equipment.
Many coupling connecting devices have been available and suggested which obviate the need of threading the conduit sections. However, these coupling connecting devices, while avoiding the need to thread the conduit, possess other drawbacks. They generally require axial pressure to contract a clamp to the conduit, a procedure which is usually difficult, awkward and inconvenient to properly achieve and otherwise possesses many other drawbacks and disadvantages.